The FBD series explosion-proof pressed in axial flow local ventilation fans for mining use (hereinafter referred to as ventilation fans) shall comply with the MT222-2007 Technical Conditions for Counterrotating Local Ventilation Fans and Q/YAF001-2011 FBD series explosion-proof pressed in axial flow local ventilation fans for mining use standards. Suitable for local ventilation in coal mine underground environments containing gas, coal dust, and other explosive hazards, and used in conjunction with positive pressure air ducts. It can also be used as ventilation equipment for tunnel construction. 1. The ventilation fan adopts computational fluid dynamics to optimize the overall design of the fan with multiple objectives. The blades are selected from the aircraft engine FMIA airfoil, which makes the high-efficiency working area of the fan large. The ventilation fan has the characteristics of compact structure, large air volume, high air pressure, long air supply distance, high effic…